U.S. patent application number 15/875585 was filed with the patent office on 2019-07-25 for functionalized filament and artificial turf prepared therefrom, and methods for making the same.
The applicant listed for this patent is TARKETT INC.. Invention is credited to Abhiram Kannan.
Application Number | 20190226161 15/875585 |
Document ID | / |
Family ID | 67299796 |
Filed Date | 2019-07-25 |
United States Patent
Application |
20190226161 |
Kind Code |
A1 |
Kannan; Abhiram |
July 25, 2019 |
FUNCTIONALIZED FILAMENT AND ARTIFICIAL TURF PREPARED THEREFROM, AND
METHODS FOR MAKING THE SAME
Abstract
The present application provides a functionalized filament for
artificial turf, a method of manufacturing said filament and a
field of artificial turf in which said filament is incorporated.
The functionalized filament for artificial turf comprising
polyolefin, such as polyethylene or polypropylene, and a
compatibilizer that has a high affinity with polyurethane. The
compatibilizers can be distributed in the filament uniformly or
non-uniformly. The compatibilizer comprises a polyolefin polymer
functionalized with various functional groups or their derivatives,
such as amine, imide, hydroxyl, acid, anhydride, or acrylic.
Inventors: |
Kannan; Abhiram; (Calhoun,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TARKETT INC. |
Farnham |
|
CA |
|
|
Family ID: |
67299796 |
Appl. No.: |
15/875585 |
Filed: |
January 19, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E01C 13/08 20130101;
C08F 255/02 20130101; D01F 1/10 20130101; D01F 8/06 20130101; C08F
10/06 20130101; D06N 2201/10 20130101; C08F 10/02 20130101; D06N
7/0065 20130101; D01F 6/46 20130101; D06N 2201/0254 20130101; D06N
7/0071 20130101; C08F 8/46 20130101 |
International
Class: |
E01C 13/08 20060101
E01C013/08; C08F 10/02 20060101 C08F010/02; C08F 255/02 20060101
C08F255/02; C08F 10/06 20060101 C08F010/06; C08F 8/46 20060101
C08F008/46; D01F 8/06 20060101 D01F008/06 |
Claims
1. A functionalized filament for artificial turf comprising a
polyolefin polymer and a compatibilizer that has a high affinity
with polyurethane, wherein the compatibilizer comprises a
functionalized-polyolefin polymer which is functionalized with a
functional group or a derivative of the functional group, wherein
the functional group is amine, imide, hydroxyl, acid, anhydride, or
acrylic and wherein a concentration of the compatibilizer in the
functionalized filament is in the range of from 2% wt to 13% wt
based on combined weights of the polyolefin polymer and the
compatibilizer.
2. The functionalized filament of claim 1, wherein the
concentration of the compatibilizer is in the range of from 2% wt
to 5.5% wt.
3. The functionalized filament of claim 1, wherein the polyolefin
polymer is polyethylene or polypropylene.
4. The functionalized filament of claim 1, wherein the functional
group is maleic anhydride.
5. A method for making an artificial turf, comprising tufting
fibers into a primary backing, spreading an infill system between
the fibers, securing the fibers to the primary backing by spreading
a polyurethane coating on the underside of the primary backing,
wherein the fiber is made of the functionalized filament of claim
1.
6. The method of claim 5, wherein the primary backing is a woven
fabric made of polypropylene, polyester, possessing needle punched
polyester, or combinations thereof.
7. An artificial turf made by the method of claim 5.
8. The functionalized filament of claim 1, wherein the filament is
a multicomponent filament.
9. A functionalized filament for artificial turf comprising a
polyolefin polymer and a compatibilizer that has a high affinity
with polyurethane, wherein the compatibilizer comprises a
functionalized-polyolefin polymer which is functionalized with a
functional group or a derivative of the functional group, wherein
the functional group is amine, imide, hydroxyl, acid, anhydride, or
acrylic, wherein the functionalized filament comprises an outermost
sheath layer and an inner core layer, wherein the outermost sheath
layer comprises the compatibilizer, wherein the inner core layer
does not comprise the compatibilizer, and wherein a concentration
of the compatibilizer in the outermost sheath layer is in the range
of from 2% wt to 13% wt based on combined weights of the polyolefin
polymer and the compatibilizer.
10. The functionalized filament of claim 9, wherein the
concentration of the compatibilizer is in the range of from 2% wt
to 5.5% wt.
11. The functionalized filament of claim 9, wherein the polyolefin
polymer is polyethylene or polypropylene.
12. The functionalized filament of claim 9, wherein the functional
group is maleic anhydride.
13. A method for making an artificial turf, comprising tufting
fibers into a primary backing, spreading an infill system between
the fibers, securing the fibers to the primary backing by spreading
a polyurethane coating on the underside of the primary backing,
wherein the fiber is made of the functionalized filament of claim
9.
14. The method of claim 13, wherein the primary backing is a woven
fabric made of polypropylene, polyethylene terephthalate,
possessing needle punched polyethylene terephthalate, or
combinations thereof.
15. An artificial turf made by the method of claim 13.
Description
FIELD OF THE INVENTION
[0001] The present application discloses a functionalized filament
for artificial turf, a method of manufacturing said filament and a
field of artificial turf in which said filament is incorporated.
The functionalized filament comprises polyolefin, such as
polyethylene or polypropylene, and a compatibilizer that has a high
affinity with polyurethane.
BACKGROUND OF THE INVENTION
[0002] Artificial turf is commonly made of a synthetic turf system
comprising at least three components, including fibers, infill and
backing. Artificial turf fibers provide comfort and safety with a
grass-like look and are commonly made of polyolefin in the
structures of the filaments including slit-films or monofilaments,
such as a polyethylene or polypropylene monofilament. Artificial
turf infill systems typically comprise infill materials (e.g., sand
or crumb rubber) which are spread between the fibers to provide
appropriate cushioning. Artificial turf backing may comprise a main
or primary backing and an adhesive (or secondary backing). The
primary backing may comprise a woven fabric made of polyolefin,
such as a polypropylene woven fabric. The artificial turf fibers
are tufted into the primary backing. Then, the artificial turf
fibers are secured by applying an adhesive, such as a polyurethane
coating, on the underside of the primary backing. The primary
backing or adhesive may include multiple layers or components
(e.g., additional layers or a layer may contain sublayers).
[0003] Polyolefins, such as polyethylene or polypropylene,
generally are relatively more nonpolar and have relatively poor
adhesion and compatibility with polar polymers or substrates, such
as polyurethane. Since the polyolefin filament and the polyurethane
coating are inherently incompatible, the incompatibility causes the
contact regions between polyolefin and polyurethane to be points of
weakness. The points of weakness can manifest as loose fibers of
the artificial turf in the form of filaments being easily pulled
out of the polypropylene woven fabric.
[0004] Existing systems or processes, however, have disadvantages
and/or have not been found to sufficient technical performance
capabilities.
SUMMARY OF THE INVENTION
[0005] The present application provides a functionalized filament
for artificial turf comprising a polyolefin polymer and a
compatibilizer that has a high affinity with polyurethane, wherein
the compatibilizer comprises a functionalized-polyolefin polymer
which is functionalized with a functional group or a derivative of
the functional group, wherein the functional group is amine, imide,
hydroxyl, acid, anhydride, or acrylic and wherein a concentration
of the compatibilizer in the functionalized filament is in the
range of from 1.5% wt to 13% by wt. based on combined weights of
the polyolefin polymer and the compatibilizer (as used herein "wt"
or "by wt. is in reference to this relationship). In one
embodiment, the concentration of the compatibilizer in the
functionalized filament is in the range of from 2% wt to 5.5%
wt.
[0006] In another embodiment, the functionalized filament for
artificial turf comprises polyolefin polymer, such as polyethylene
or polypropylene, and a compatibilizer that has a high affinity
with polyurethane, wherein the compatibilizers can be distributed
in the filament either uniformly or non-uniformly, wherein the
filament can be a multicomponent filament. The compatibilizers can
be distributed uniformly by applying a process in which the
compatibilizers is mixed or blended with the polyolefin to provide
a general even distribution. A non-uniform distribution can also be
possible for example by performing a limited duration of
blending.
[0007] The compatibilizer of the functionalized filament of the
present application comprises a polyolefin polymer functionalized
with various functional groups or their derivatives, such as amine,
imide, hydroxyl, acid, anhydride or acrylic. In a preferred
embodiment, the functional group is an anhydride derived from
maleic acid, such as maleic anhydride. In this embodiment, the
compatibilizer comprises polyolefin polymer chains modified with
anhydride functional groups. The concentration of the
compatibilizer in the functionalized filament is in the range of
from 2% wt to 13% wt based on the total weight of the
functionalized filament, i.e., the combined weights of polyolefin
and compatibilizers. The weight of the compatibilizer includes the
weights of the modified polyolefin polymer and the functional
groups. In a preferred embodiment, the concentration of the
compatibilizer in the functionalized filament is at least 2%. In
another preferred embodiment, the concentration of the
compatibilizer in the functionalized filament is in the range of
from 2% to 5.5%.
[0008] The present application also provides a method for making an
artificial turf, comprising tufting fibers into a primary backing,
spreading an infill system between the fibers, securing the fibers
to the primary backing by spreading a polyurethane coating on the
underside of the primary backing, wherein the fiber is made of the
functionalized filament of the present application. In a preferred
embodiment, the primary backing is a woven fabric made of
polypropylene. In another embodiment, the primary backing is a
woven fabric made of polyester. In another embodiment, the primary
backing is a woven fabric made of polypropylene and possessing
needle punched polyester or polypropylene fibers. In one aspect,
the primary backing is a woven fabric made of polypropylene,
polyester, possessing needle punched polyester, or combinations
thereof. The present application also provides an artificial turf
that is made by the method of the present application by
incorporating the functionalized filaments of the present
application.
[0009] In yet another aspect, the present application provides
functionalized filament for artificial turf comprising a polyolefin
polymer and a compatibilizer that has a high affinity with
polyurethane, wherein the compatibilizer comprises a
functionalized-polyolefin polymer which is functionalized with a
functional group or a derivative of the functional group, wherein
the functional group is amine, imide, hydroxyl, acid, anhydride, or
acrylic, wherein the functionalized filament comprises an outermost
sheath layer and an inner core layer, wherein the outermost sheath
layer comprises the compatibilizer, wherein the inner core layer
does not comprise the compatibilizer. In one embodiment, the
concentration of the compatibilizer in the outermost sheath layer
is in the range of from 2% wt to 10% (2.5% wt to 10.5% wt for
single component) wt based on combined weights of the polyolefin
polymer and the compatibilizer. Even in the single component
filament, it should be understood that the objective is to have a
concentration of 2% wt to 10% wt in the outer area of the single
component structure. As mentioned herein, 0.5% is added to
composite for the structural difference.
[0010] In addition, the present application provides a
functionalized filament for artificial turf comprising a polyolefin
polymer and a compatibilizer that has a high affinity with
polyurethane, wherein the compatibilizer comprises a
functionalized-polyolefin polymer which is functionalized with a
functional group or a derivative of the functional group, wherein
the functional group is amine, imide, hydroxyl, acid, anhydride, or
acrylic, wherein the functionalized filament comprises an outermost
sheath layer and an inner core layer, wherein the outermost sheath
layer comprises the compatibilizer, wherein the inner core layer
does not comprise the compatibilizer, and wherein a concentration
of the compatibilizer in the outermost sheath layer is in the range
of from 2% wt to 10% wt based on combined weights of the polyolefin
polymer and the compatibilizer. In one embodiment, the
functionalized filament contains multiple sheath layers and core
layers, wherein the fiber comprises at least two components,
wherein the outermost sheath layer comprises polyolefin, such as
polyethylene or polypropylene, and a compatibilizer that has a high
affinity with polyurethane, wherein the inner sheath and core
layers comprise polyolefin polymers, such as polyethylene,
polypropylene or their blends. In a preferred embodiment, the
functionalized multicomponent fiber comprises 2-6 components. In
another preferred embodiment, the functionalized multicomponent
fiber comprises two components.
[0011] The compatibilizer in the outermost sheath layer of the
functionalized multicomponent fiber of the present application
comprises a polyolefin polymer functionalized with various
functional groups or their derivatives, such as amine, imide,
hydroxyl, acid, anhydride, or acrylic. In a preferred embodiment,
the functional group is an anhydride derived from maleic acid, such
as maleic anhydride. In this embodiment, the compatibilizer
comprises polyolefin polymer chains modified with anhydride
function groups. The concentration of the compatibilizer in the
outermost sheath layer of the functionalized multicomponent fiber
is in the range of from 2% wt to 10% wt based on the total weight
of the outermost sheath layer, i.e., the combined weights of
polyolefin and compatibilizer in the outermost sheath layer. The
weight of the compatibilizer includes the weights of modified
polyolefin polymer and functional groups. In a preferred
embodiment, the concentration of the compatibilizer in the
outermost sheath layer is at least 2% wt. In another preferred
embodiment, the concentration of the compatibilizer in the
outermost sheath layer is in the range of from 2% wt to 5% wt.
[0012] The present application also provides a method for making an
artificial turf, comprising tufting fibers into a primary backing,
spreading an infill system between the fibers, securing the fibers
to the primary backing by spreading a polyurethane coating on the
underside of the primary backing, wherein the fiber is made of the
functionalized multicomponent fiber of the present application. In
a preferred embodiment, the primary backing is a woven fabric made
of polypropylene. In another embodiment, the primary backing is a
woven fabric made of polypropylene and polyethylene terephthalate
(PET). In another embodiment, the primary backing is a woven fabric
made of polypropylene and possessing needle punched PET fibers. In
one aspect, the primary backing is a woven fabric made of
polypropylene, polyethylene terephthalate, possessing needle
punched polyethylene terephthalate, or combinations thereof. The
present application also provides an artificial turf, which is made
by the method of the present application by incorporating the
functionalized multicomponent fibers of the present
application.
[0013] The details of the preferred embodiments of the present
application are set forth in the accompanying figures and detailed
description herein. Once these details of the application are
known, numerous additional innovations and changes, which are
within the scope of this application, will become obvious and
implementable to one of ordinary skill in the art.
BRIEF DESCRIPTION OF THE FIGURES
[0014] Further features of the inventive concept, its nature and
various advantages will be more apparent from the following
detailed description, taken in conjunction with the accompanying
figures:
[0015] FIG. 1 shows a magnified view of a cross section of an
illustrative multicomponent filament fiber comprising a core layer
and a sheath layer, wherein the compatibilizer is present only in
the sheath layer of a multicomponent filament in accordance with
embodiments of the present invention. The distribution of the
compatibilizers in the sheath layer is illustratively represented
by the dots but it is not necessarily to scale.
[0016] FIG. 2 shows a magnified view of a cross section of an
illustrative monofilament fiber, wherein the compatibilizers are
incorporated throughout the cross section of the monofilament fiber
in accordance with embodiments of the present invention. The
distribution of the compatibilizers in the monofilament fiber is
illustratively represented by the distribution of the dots, but it
is not necessarily to scale.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Throughout this description, the preferred embodiments and
examples provided herein should be considered as exemplar, rather
than as limitations of the present application.
[0018] The present application discloses a functionalized filament
for artificial turf, a method of manufacturing said filament and an
artificial turf (e.g., a field made of artificial turf, the
assembled backing and fibers prior to installation e.g., without
infill) in which said filament is incorporated.
[0019] Polyolefin polymers, such as polyethylene and polypropylene,
are used to manufacture yarns or fibers for producing artificial
turf in order to achieve improved wear-resistance, flexibility,
mechanical properties and processability. In one embodiment,
polyolefin polymers are extruded to form filaments and further
processed into bands. Several bands are twisted to form a yarn.
Several yarns may be twined to form a composite yarn. In some
embodiments, co-extrusion is used to manufacture the yarns, such as
building a core and a cladding. In some embodiments, a
multicomponent fiber comprising a sheath and a core is made of
polyethylene filaments. A multicomponent in this context refers to
the structure of the fiber being made of two or more layers (e.g.,
a core and an outer layer).
[0020] In order to improve the compatibility between polyolefin
polymers and polar substrates, such as polyurethane, a
compatibilizer is introduced into the polyolefin polymers during
extrusion. The present application provides a functionalized
filament for artificial turf, which is made of polyolefin polymers,
such as polyolefin blend compositions containing functionalized
polyolefin polymers as compatibilizers. In one embodiment, a
compatibilizer, such as a maleic acid derivative of polyethylene,
is introduced into the polyethylene filament during the
manufacturing extrusion process. In a preferred embodiment, the
maleic acid derivative is maleic anhydride. The compatibilizer is
introduced into the polyethylene filament during the manufacturing
extrusion process to be distributed throughout the filament (or
layer, as it should be understood in a multicomponent structure)
from which a functionalized polyethylene filament can be obtained.
In some embodiments, a single component fiber is made of
polyethylene filament comprising compatibilizers, wherein some of
the compatibilizers are situated on the surfaces of the fibers to
maximize the compatibility between the fiber and the polyurethane
coating. In some embodiments, a multicomponent fiber comprising a
sheath and a core is made of polyethylene filament comprising
compatibilizers. In a preferred embodiment, a multicomponent fiber
comprising a sheath and a core is made of polyethylene filament
comprising compatibilizers, wherein the sheath comprises
compatibilizers, wherein the core does not comprise
compatibilizers. In a preferred embodiment, a multicomponent fiber
comprising multiple sheaths and cores is made of polyethylene
filament comprising compatibilizers, wherein the outermost sheath
comprises compatibilizers, wherein the inner sheath and core do not
comprise compatibilizers.
[0021] In one embodiment, a modified polyethylene filament is
obtained by introducing the compatibilizers into the polyethylene
filament during the manufacturing extrusion process to distribute
the compatibilizers throughout the polyethylene filament. When the
surfaces of the modified polyethylene filaments are contacted with
a polyurethane coating, the affinity between the modified
polyethylene filament and the polyurethane coating is much higher
than that of the unmodified polyethylene filament by several orders
of magnitude. The increased affinity promotes the penetration of
the polyurethane into the filament bundle and improves the adhesion
between the polyethylene filament and the polyurethane coating to
secure the polyethylene filament in place.
[0022] The present application provides a functionalized filament
for artificial turf, which is made of polyolefin blend compositions
containing functionalized polyolefin polymers as compatibilizers. A
modified polyethylene filament is obtained by introducing the
compatibilizers into the polyethylene filament during the
manufacturing extrusion process to distribute the compatibilizers
throughout the polyethylene filament. The modified polyethylene
filament has excellent adhesion properties toward polar polymers or
substrates, such as polyurethane, when polyolefin blend
compositions containing at least 2% wt functionalized polyolefin
polymers (i.e., compatibilizers), preferably in the range of from
2% wt to 5.5% wt, 2% wt to 10.5%, or from 2% wt to 13% wt based on
the combined weights of the polyolefin polymers and functionalized
polyolefin polymers.
[0023] The polyolefin in the polyolefin blend compositions of the
present application can for example include high density
polyethylene (HDPE), low density polyethylene (LDPE), metallocene
linear low density polyethylenes (LLDPE), homogeneously branched
linear ethylene/.alpha.-olefin interpolymers, homogeneously
branched substantially linear ethylene/.alpha.-olefin
interpolymers, or combinations thereof.
EXAMPLE
[0024] The following examples illustrate the benefits and
advantages of the present application.
Example 1. The Addition of Compatibilizers in Multicomponent
Filaments
[0025] A series of multicomponent fiber filaments comprising a core
layer (14) and a sheath layer (10) were made using extrusion,
wherein the compatibilizer was present only in the sheath layer of
a multicomponent filament. The distribution of the compatibilizers
in the sheath layer (10) is illustratively represented by the
distribution of the dots (12), not necessarily to scale (meaning it
may show greater density than actual for illustration purposes), in
FIG. 1. A series of bicomponent filaments having a cross section as
shown in FIG. 1 were extruded using two or three grades of Linear
Low Density Polyethylene ("LLDPE") polymers, i.e. LLDPE1, LLDPE2,
or LLDPE-g-MA. Linear Low Density Polyethylene grafted with Maleic
Anhydride (LLDPE-g-MA) was purchased from Sigma-Aldrich. The core
layer is made of LLDPE1 (a linear low density polyethylene having a
density of 0.92 gm/cc as per ISO 1183 and a melt index of 0.5 gm/10
min as per ISO 1133) at a fixed loading weight percentage of 45%.
The sheath layer is made of LLDPE2 (a linear low density
polyethylene having a density of 0.92 gm/cc as per ISO 1183 and a
melt index of 0.9 gm/10 min as per ISO 1133) in the range of from
37.5% to 55% and LLDPE-g-MA in the range of from 0% to 17.5%. The
formulations of LLDPE1, LLDPE2 and LLDPE-g-MA for the series are
provided in Table 1.
TABLE-US-00001 TABLE 1 Bicomponent filament formulations Core
Sheath Iteration Wt % LLDPE 1 Wt % LLDPE 2 Wt % LLDPE-g-MA 1 45 55
0 2 45 53 2 3 45 50 5 4 45 47.5 7.5 5 45 45 10 6 45 42.5 12.5 7 45
40 15 8 45 37.5 17.5
[0026] The produced series of bicomponent filaments were
incorporated to turf carpet by first tufting the filaments onto a
primary backing made of polypropylene woven fabric, and
subsequently the primary backing was coated with polyurethane
adhesive. The weight of the polyurethane coating applied to the
primary backing was between 16 and 22 oz per sq yard of turf.
[0027] The strength at the point of contact between polyurethane
(PU) and polyethylene (PE) filaments was quantified in a standard
test by measuring the force (in lbf) required to release a single
filament from the turf backing. When the force was applied on an
individual filament, there were two results. The filament was
released from the turf by leaving a clean break at the point of
contact, or alternatively the filament slipped out from the turf in
its entirety. This test was repeated a hundred times per each
iteration, noting each time if a filament broke or slipped from the
turf i.e. at the point of PU-PE fiber contact. The statistics of
the number of breaks and slips including the average values and
standard deviations for the break force and slip force (lbf) are
provided in Table 2.
TABLE-US-00002 TABLE 2 Statistical results for the single filament
pull tests conducted on the bicomponent filaments that were
prepared based on the formulations as described in Table 1. Wt %
LLDPE-g- No. of Slips No of Breaks MA (Per 100 pulls) (Per 100
pulls) 0 100 0 2 92 8 5 75 25 7.5 66 34 10.0 64 36 12.5 52 48 15.0
46 54 17.5 39 61
[0028] The data in Table 2 illustrates the relationship between the
wt % of the compatibilizer (i.e., LLDPE-g-MA) and physical
performance at the point of contact between PE and PU. With the
incorporation of the compatibilizer, the propensity of filaments to
slip out is diminished. At 5% loading of the compatibilizer
(LLDPE-g-MA), 25% of the filaments tested showed no slippage. In
other words, 25% of the filaments tested did not slip out from the
turf in their entirety, instead these filaments were released from
the turf by leaving clean breaks at the point of PU-PE contact
(i.e., number of breaks). This data was referring to number of
breaks per 100 pulls in Table 2. Since the tested filaments were
strongly affixed in the turf, the applied force was strong enough
to break these filaments at the point of PE-PU contact. Note also
the results at 2% by weight is considered to be significant by
those of ordinary skill in the art given that the low loading
provided performance improvements that were unexpected.
[0029] The trend continued with increasing loading wt % of the
compatibilizer. At 17.5% loading of the compatibilizer, the
majority of the filaments stay strongly affixed in the turf with
only 39% of the filaments opting to slip out from the turf during
testing.
Example 2. The Addition of Compatibilizer in Single Component
Monofilament Fibers
[0030] Seven different grades of polyethylene copolymers
functionalized with amine, imide, hydroxyl, acid, anhydride or
acrylic groups as described in Table 3 were procured from different
industrial and academic suppliers. Grades 1A and 1B were both low
density polyethylene (LDPE) copolymers, having a density of 0.85
gm/cc. Grade 1A was functionalized using amine. Grade 1B was
functionalized using imide. Both Grades 1A and 1B were obtained
from Sigma Aldrich. Grades 1C through 1F were copolymers of linear
low density polyethylene (LLDPE) having a density range between 0.9
and 0.92 gm/cc, which were obtained from industrial suppliers.
Grade 1G was an acrylic ester based polyethylene copolymer. A
series of monofilament fibers were made through extrusion using
these functionalized polyethylene copolymers as compatibilizers,
wherein the compatibilizers were incorporated throughout the
monofilament fiber (20) as shown in FIG. 2. The distribution of the
compatibilizers in the monofilament fiber is illustratively
represented by the distribution of the dots (22), not necessarily
to scale, in FIG. 2.
[0031] Monofilament fibers having a cross section depicted in FIG.
2 were extruded by incorporating 5% of the respective
compatibilizer grades of polyethylene copolymers and 95% LLDPE2 (a
linear low density polyethylene having a density of 0.92 gm/cc as
per ISO 1183 and a melt index of 0.9 gm/10 min as per ISO 1133).
Seven iterations of functionalized filaments were produced by
extrusion using Grades 1A-1G of functionalized polyethylene
copolymers respectively. An 8.sup.th control grade of polyethylene
copolymer having the same geometry as other grades was produced
without incorporating any compatibilizer.
[0032] The extruded monofilaments were incorporated to turf carpet
by tufting onto a primary backing made of polypropylene woven
fabric, and then a second step of polyurethane coating was applied
to the underside of the carpet, i.e., onto the underside of the
primary backing. The weight of the polyurethane coating applied was
maintained between 16 and 22 oz per sq yard of turf. The strength
at the point of contact between polyurethane and the turf filaments
was quantified in a standard test by measuring the force (lbf)
required to release a single filament out of the turf. This test
was repeated a hundred times per each iteration, noting each time
if a filament broke or slipped out from the turf i.e., at the point
of PU-PE (polyurethane-polyethylene) contact. The statistics of the
number of breaks and slips including the average values and
standard deviations for the break force and slip force (lbf) are
provided in Table 4.
TABLE-US-00003 TABLE 3 Grades and characteristics of
compatibilizers Iteration Grade Carrier Resin Functional Group
Weight % added 1 1A LDPE Amine 5% 2 1B LDPE Imide 5% 3 1C LLDPE
Hydroxyl 5% 4 1D LLDPE Acid 5% 5 1E LLDPE Anhydride 5% 6 1F LLDPE
Anhydride 5% 7 1G Ethylene Acrylic 5% Acrylic Ester
TABLE-US-00004 TABLE 4 Statistical results for the single filament
pull tests conducted on the monofilament fibers that were prepared
based on the formulations as described in Table 3. Avg Std Dev Slip
Force Slip Force No of Slips No of Breaks Grade (lbf) (lbf) (Per
100 Pulls) (Per 100 Pulls) Control 2.94 0.62 100 0 1A 3.08 0.56 46
54 1B 3.05 0.45 43 57 1C 3.41 0.48 58 42 1D 3.31 0.43 37 63 1E 3.27
0.53 50 50 1F 3.57 0.58 67 33 1G 3.85 0.45 60 40
[0033] The data in Table 4 shows the impact of each of the
different grades toward improving the resistance to slip at the
point of contact between PE filaments and PU coating. Addition of
5% wt of the compatibilizer increased the average force required to
release a filament from the turf when compared to the control
filament without the addition of compatibilizer. The least
improvement over the control is observed in fibers based on 5% 1A
and 1B grades respectively, while the most improvement at 5%
loading is exhibited by filaments based on 1D, 1F and 1G grades.
Fibers based on the other grades fall between these two extremes.
All grades show a statistically significant improvement in
resistance to filament pull out.
[0034] As illustratively described herein, the addition of a
functionalized-polyolefin polymer provides performance improvements
at a lower percentage or a lower range of percentages by weight
than what expected. It was not expected to see improvements in
performance at a low rate(s) such as at 2% by wt, 5% by wt, 7.5% by
wt, 10% by wt, or 12.5% by wt (% wt of compatibilizer in a
functionalized filament). It was also not expected to see such
significant performance improvement at 5% by wt. This is shown in
the provided test data and results. It is also reasonable to infer
an appropriate low range that is effective from this information
such as 2% to 13%, 2% to 10.5%, 2% to 8%, 2% to 5.5%, 5% to 7.5%,
and 5% by wt (of compatibilizer in the functionalized filament). A
value recited herein for the percentage by weight of compatibilizer
is understood to be associated with a small percentage of variation
so that it incorporates an approximation of +/20%, such as 5%+/-20%
(of the 5%). The artificial filament can be a filament that
comprises a polyolefin polymer and a compatibilizer comprising a
functionalized-polyolefin polymer which is functionalized with a
functional group or derivative of a functional group, wherein the
functional group is selected from the group: amine, imide,
hydroxyl, acid, anhydride, or acrylic, and the functionalized
polyolefin polymer has a concentration of compatibilizer in the
functionalized filament in the range of 2% to 13%, 2% to 10.5%, 2%
to 8%, 2% to 5.5%, 5% to 7.5%, and 5% by wt (of compatibilizer in
the functionalized filament). In preferred embodiments, the
compatibilizer is a functionalized polyolefin polymer which is
functionalized with a functional group or derivative of the
functional group wherein the functional group is selected from the
group: amine, imide, hydroxyl, acid, anhydride, or acrylic.
[0035] It should be understood that in multicomponent fiber
embodiment, the outer sheet or layer is functionalized to produce a
functionalized filament. The illustrative description, examples,
and testing involved a "single" component filament. In the case of
a multicomponent filament, the outer layer having an exterior
exposed surface that touches the primary backing and/or adhesive is
formed to include the desired compatibilizer, as discussed herein
(other layers can be produced without the compatibilizer if
desired). In such an arrangement, the percentage by weight of the
compatibilizer in the functionalized filament can be lower because
the likely thinner outer layer will cause more of the
compatibilizer to be on or close to the surface.
[0036] A recitation of a range should be understood to include the
end points of the range. The percentage by weight is based on the
total weight of the functionalized filament, i.e. the combined
weights of polyolefin polymer and compatibilizers, which is the
primary or substantially all of the material used in producing a
filament. The filament is produced through polymer extrusion by
mixing the polyolefin polymer and the compatibilizers in melting
state. The concentration of the compatibilizer in the
functionalized filament is in the range of from 2% wt to 13% wt
based on the total weight of the functionalized filament, i.e., the
combined weights of polyolefin and compatibilizers. The weight of
the compatibilizer includes the weights of the modified polyolefin
polymer and the functional groups. The composition can be blended
using solids (based on the desired percentage by weight), melted,
and blended.
[0037] Given that the experiments were directed to a bicomponent
structure, a reasonable estimation has been made based on
scientific knowledge to increase the percentage by weight of
compatibilizer by 0.5% in the description herein when in context
the discussion is applicable to filaments in general (single
component filament and multicomponent filament).
[0038] The composition, structure, and manufacturing process of
conventional artificial turf fibers or filaments are generally
known to those of ordinary skill in the art. This for example
includes the knowledge of the different components that are
combined to produce a filament.
[0039] The shape, surface texture or feature (e.g., bumps),
geometric attributes, or other aspects that can affect a
cross-sectional profile of filament will not in general affect
(improve, reduce, modify, etc.) the effectiveness of embodiments of
the present invention (in providing better fiber retention).
[0040] It is understood that the present application is not to be
limited to the exact description and embodiments as illustrated and
described herein. To those of ordinary skill in the art, one or
more variations and modifications will be understood to be
contemplated from the present disclosure. Accordingly, all
expedient modifications readily attainable by one of ordinary skill
in the art from the disclosure set forth herein, or by routine
experimentation therefrom, are deemed to be within the true spirit
and scope of the invention as defined by the appended claims. It is
understood by those of ordinary skill in the art that a broader or
specific scope of invention based on the provided description or
figures are contemplated without the need for explicit recitation
in the current application.
[0041] It would be understood that the various sizes, materials,
configurations and arrangements disclosed herein may be combined
and constructed in any way that is feasible to create a new
filament, artificial turf comprising the filaments, or process for
making the filament for the field of artificial turf systems, in
particular athletic fields. Unless defined otherwise, all technical
and scientific terms used herein have same meaning as commonly
understood by one of ordinary skill in the art to which this
invention belongs. Also, as used herein and in the appended claims,
the singular form "a", "and", and "the" include plural referents
unless the context clearly dictates otherwise. To the extent, an
order of process steps is described, one of ordinary skill in the
art will be able to understand the order of steps may be varied (or
steps eliminated) without the need for the application to
explicitly explain such variations.
* * * * *